272 BACTERIOLOGY 



Gelatin colonies. Deep: brown, entire, homogeneous. Surface: light 



brown; margins irregular; centres dense, becoming, in 3 days, liquefied, 



crateriform, 4 mm., with, white irregular centres and greenish borders, 



in which are tangled filaments. 

 Agar slant. Growth white, glistening, elevated, sometimes yellowish ; odor 



of sour milk. 

 Gelatin stab. Liquefaction crateriform, becoming stratiform or infundibuli- 



form. 

 Potato. Growth elevated, white, moist, glistening, spreading, rugose, becoming 



smoother ; odor of stale milk. 

 Bouillon. Turbid, with a flocculent sediment, becoming clear. 

 Litmus milk. Decolorized slowly, and peptonized; amphoteric alkaline. 



Indol negative. Grow at 36 .' 

 Habitat. Soil. 



177. B. Scheurleni Sternberg 



Manual, 1892, 680; Dyar, I.e., 367. 



Morphology. Bacilli 0.7-1.0: 1.0-2.5 /"> occur singly and in short chains. 

 Agar slant. Growth thin, transparent. Grow slowly at room temperature. 

 Habitat. Isolated from the surface of the skin, mammae of woman, air, etc. 



178. B. liodermos Flugge 



Die Mikroorganismen, 1886. 



Morphology. Bacilli thick, rounded, 1.2 : 3.5 fx ; in pairs and chains. 

 Gelatin stab. Liquefaction infundibuliform ; a membrane on the surface. 

 Agar slant. Growth a white, rosette-like layer. 

 Potato. A gummy, translucent layer ; gum soluble in water, precipitated by 



alcohol. 

 Milk. Coagulated, peptonized ; butyric acid. Related to, perhaps a variety oL 



B. vulgatus. 

 Habitat. Isolated from potato and from milk. 



179. B. mesentericus Trev. 



B. mesentericus-fuscus Flugge: Die Mikroorganismen, 1886. 

 B. mesentericus Trevisan : Genera, 1889, 19. 



Morphology. Bacilli 0.8 : 2-4 fi ; ends rounded. Stain by Gram's method. 



Gelatin colonies. Deep colonies gray-yellow, irregular, with outgrowths. 

 Surface colonies, small, round, gray-white, becoming sunken in the gelatin 

 like B. subtilis. Microscopically, centres gray-brown, opaque, with ciliate 

 borders. 



